I guess it's a cultural thing that in Western countries 'chin shaving' is not done as often as advancement; my understanding is that it is very common in some Asian countries, and it is also a standard part of facial feminisation surgery which is a procedure that more and more maxillofacial surgeons specialize in. I do not think a 'cosmetic surgeon' (whatever you mean by that) should be messing around with chin osteotomies, that is definitely an area for a qualified maxillofacial surgeon.
I'm aware of asian countries like Korea being very into shaving procedures but those are much different than what I require or am interested in.. Those countries are approaching it as a method to shave down the entire jaw line and the sides of the chin to get a very "V" like shape with a point right at the tip of the chin, not so much a reduction of the projection of the chin..
I personally just need my chin to sit back in proportion to the projection of my lips, and if its being shaved it would have to be done in a way that maintained a good (or even the same) over all shape, only less long. It's nothing to do with masculine/feminine, only distance it sticks out in front of the lips. Which I imagine would require a very aesthetic/subtle (cosmetic) approach.
And I'm not sure if there is a language barrier here or if I'm mistaken, but what I meant by "cosmetic" or you could say "plastic" surgeon is someone who specializes in shaping things in an aesthetic way that compliments the rest of the face.. a "cosmetic" surgeon would be the same as someone who specializes in anything like rhinoplasty or breast augmentation. As far as I'm aware many maxillofacial surgeons who perform mostly jaw surgeries do not always take aesthetics into consideration. I've seen it mentioned that for them if the jaws align well and the bite is correct after surgery then that is all that matters, regardless of whether or not the patient is unhappy with the overall altered appearance of their face afterward. I was under the impression that is the reason someone like Dr. Gunson gets so much attention, because he is one of the few maxillofacial surgeons who does put so much attention toward aesthetic outcomes as well as function/bite.